<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="jquery-1.12.2.min.js"></script>
    <script>
        //点击按钮,改变按钮的value值,鼠标进入到按钮中,按钮的宽改变,高改变,鼠标离开的时候,按钮的背景颜色为绿色
        $(function () {
            $("#btn").click(function () {
                $(this).val("改变了");
            }).mouseover(function () {
                $(this).css({"width":"200px","height":"100px"});
            }).mouseout(function () {
                $(this).css("backgroundColor","green");
            });
        });
    </script>
</head>
<body>
<input type="button" value="显示效果" id="btn"/>
</body>
</html>